1. Field of Invention
The invention relates to a method for managing the problem of abnormal booting in a multiple processor computer system. More particularly, the invention relates to a method that uses a baseboard management controller (BMC) to switch among central processing units (CPUs) or read only memory (ROM), thereby managing the problem of abnormal booting.
2. Related Art
Based upon the design concept of highly available systems, it is necessary to have a backup system in order to maintain the normal functioning of the system without any manual problem shooting. This is the main reason for the existence of multiple processor systems. A multiple processor computer system such as a server has several CPUs. Therefore, the system has a higher efficiency and can replace a defective CPU if any error occurs.
The booting procedure for a multiple processor computer system is done by assigning a CPU as the boot CPU (boot strap processor) to process BIOS commands during booting process, initializing the computer system and loading in the operating system (OS). The boot BIOS is stored in the BIOS ROM. Other CPUs during the booting process are defined as application processors and set in the wait state.
When the boot CPU cannot boot, a conventional method is to encode in the BIOS a CPU switching program so that the system can switch from the boot CPU to another application processor. The switching mechanism is shown in FIG. 1.
Another possible problem is that after the boot CPU has been switched to all other CPUs the system and the boot BIOS still cannot boot. This happens when the BIOS ROM is out of order. To solve the BIOS disorder problem, one or even many backup ROM's are proposed as the substitute solution. The backup BIOS stored in a backup ROM is used to restart the booting process. The switching mechanism is shown in FIG. 2.
However, the drawback of the above-mentioned method is that one has to encode a special BIOS to switch the CPUs or to design the ROM boot swap to switch between the BIOSs stored in ROMs. Its electronic circuit is more complicated.